Terminal-exhaust steam-engine.



J. DAVIDSON. TERMINAL EXHAUST STEAM ENGINE.

APPLICATION FILED MAYZO, 1911. 1,084,404.

f t Zing; e6. M

Jtiarzzqw I Patented Jan. 13, 1914.

sir :XTES PATENT OFFICE.

JOHN DAVIDSON, F PENDLETON, ENGLAND.

TERMINAL-EXI-LAUST STEAM-ENGINE. 1

To all whom it may concern: I

Be it known-that 1, JOHN DAVIDF N, a

' subject of the King of Great Britain, residing at- Pendleton, in thecounty 0E Lancaster, Kingdom of Great Britain, have invented certain newand useful Improvements in Terminal-Exhaitst Steam-Enginesmf which'lltlt'l-lllfl' from the efficiency of the'cngine.

For this purphse T jacket the cylinder in the usual way around thebarrel and cylinder head as far as practicable, but. in order. toincrease the oiliciency of the jacket, I cause the steam to circulatearound the barrel and afterward across the cylinder head, or in thereverse direction before entering the cylinder through the admissionvalve.

ln the ease of small engines where the admission valves have a.thoroughfare through them, l cause one halt only of the steam to passtluough the jacket. l, attain this object by the means illustrated inthe accompanying drawings, in which-r Fieure l is a lon nudmal sectionof a cen- D a tral exhaust cylinder constructed in accordance with one,embodiment of my invention,'

and Fig. 2 av fragmentary longitudinal section of a central exhaustcylinder constructed in accordance with another embodiment. Similarletters refer to similar parts throughout the several views.

, Referring to the drawing a are the-steam inlets, b the steam jacketsaround the cylin- (ler ends, communicating with the said steam inlets,r: the steam admission ports leading from the steam admission valvecasing (Z to the cylinder, 0 the cylinder heads which have. each achamber f and twopas- Specification of Letters Patent. Patented Jan, 131914. Application. filed. May 0,1911. SeriaiNo. 628,370.

sagesg and h leadingitherefrom, the formerto the valve cas ng d and thelatter to the jacket 6.

Referring. to- Fig. 1, according to one embodiment of .my' inventionandwhen emplayingsteam admission valves ii-having n0 thoroughfare the wholeof the steam asses from the inleta first into the jac et 6 around thecylinder end,.then through the passages h and chamber mission valve andport a into the cylinder or vice-versa, the steam from the inlet apasses first through .the nssage g,..chamber f,- passage h in the cyinder head, then through the jaoketb' and finally through the admissionvalve and-port o intothe cylinder. 4 In the drawing the lower .valve isshown in its open position and the'arrows indicate the path taken by thesteam. r

Referring .to Fig. 2 hich illustrates another embodiment-of anyinvention ,-'more particularly applicable to small engines provided withtubular steam admission valves and having a comparatively small area tobe heated, only one half of the steam is utilized for heating beforeenterin the cylinder'and the other half is allowe to'pass directly intothecylinder. For this'purposc the passage 7.: to the valve isrestricted, so

that when the steam admission valve 1 is open only one half of the steamwill pass from the inlet through the passage is and the inner end of theadmission valve 1 into the port ,0 and the cylinder as indicated in thedrawings by an arrow;- The other half of'the steam is caused to passfrom the'inlet c'into the jacket 6 around the cylinder end, then acrossthe passage h, chamber f and passage {fin the cylinder head e to theouter end of the admission valve 1 and enters the port (1 and thecylinder through the outerend of the admission valve 1 as indicated inthe drawings also by an arrow.

I claim: in a central exhaust steam, engine having a live steamadmission valve at, and a steamja'cket around each .end of the cylinderand a steam chamber in each cylinder head, a.

passage 9 in the cylinder head a and final y through the aid-.-

steam inlet in proximity to the said velve "and in communication withthe said steam jacket, a passage connectin the said 'steem necting thesa'id-steamchamber and the said valvetogether, for the purpose ofcompelling live steam to circulatethrough the said steam jacket andsteam chamber-beforeen- 1 teringithe said valve. Y

In testimony whereof I have aflixed my signature-in presence 0itwowitness es. v

'JOHNYDAVIDSOKL Witnesses:

' FERDINAND B. Bossrmnnr,

STANLEY E. BRAMALL.

